pkgsrc/licenses

Hi,
I want to import font packages to pkgsrc.
See wip/konatu-ttf and wip/ricty-ttf.
These fonts are released under licenses that is not registered
in pkgsrc/licenses directory.
konatu-ttf is released under Creative Commons
Attribution-ShareAlike 3.0 Unported
http://creativecommons.org/licenses/by-sa/3.0/ .
Can I add this CC BY-SA 3.0 unported license to pkgsrc/licenses?
CC has many variation, CC {BY|BY-ND|BY-SA|BY-NC|BY-NC-ND|BY-NA-SA}
{1.0|2.0|2.5|3.0} {Unported|Generic|English|Japanese|...} and so on.
eicty-ttf is released under licenses that are already registered in
pkgsrc/licenses (ipafont and open-font-license), and M+ font license.
You can read M+ font license in
http://mplus-fonts.sourceforge.jp/mplus-outline-fonts/index-en.html#license .
Can I identify this license as other license that is already registered
in pkgsrc/licenses? Or can I add this to pkgsrc/licenses?
Thank you.
--
Ryo ONODERA // ryo_on%yk.rim.or.jp@localhost
PGP fingerprint = 82A2 DC91 76E0 A10A 8ABB FD1B F404 27FA C7D1 15F3